a) Field of the Invention
The invention relates to an apparatus for transmitting digital data between any first party and a second party assigned to this first party, wherein the parties belong to a single, common or to two mutually independent narrowband integrated services digital networks (N-ISDN networks).
b) Background of the Related Art
The N-ISDN network (Narrowband Integrated Services Digital Network), referred to above is understood to be a digital telecommunication network, which integrates various duties and for which the transmission up to the users, that is, up to the end use equipment, such as telephone equipment, is accomplished digitally. The bit rate of a channel is 64 kbit/s, which corresponds to the PCM standard (Pulse Code Modulation) (scanning values of, in each case, 8 bits (octet) in the repetition cycle of 8 kHz). There exists extensive standards documentation and literature dealing with ISDN technology.
Digital transmission, differently organized and with a band broader by several orders of magnitude, is being provided at the present time through the ATM Networks (Asynchronous Transfer Mode). These networks are actual transport networks, on which addressed cells operate synchronously, it being possible for the parties to insert these cells into the network or to take them out at any time in an asynchronous manner. A cell consists of a header of 5 octets (40 bit) and a payload of 48 octets for transporting useful information. There also exists standards information and literature concerning ATM networks.
It is now desirable and advantageous and is a general object of the invention that said networks can be interlinked with one another. This means that it must be possible to indicate network adaptors, with the help of which it is possible to bring useful information from the one network into the other and the reverse. From this, there results a particular object of the present invention, that is, to provide such a network adaptor, which is simple in construction and with the help of which good utilization of the transmission capacities of the two networks is possible.
In accordance with the present invention, an apparatus for transmitting digital data between any first party and a second party assigned to the first party, the parties belonging to a single, common or two mutually independent N-ISDN networks comprises that the N-ISDN network or networks altogether have at least two ISDN nodes, an ATM network having at least two ATM nodes and at least two network adaptors. The two network adaptors have at least one ISDN node and at least one ATM node connected to them over incoming and outgoing lines of a respectively assigned network norm. The network adaptors are constructed free of blockages for receiving time-multiplexed octets from the lines coming in from the respective N-ISDN network or sending out time multiplexed octets on the lines going out to the respective N-ISDN network. The network adaptors are also for sending out and receiving cells on the lines going out to the ATM network and from the lines coming in from the ATM network respectively. The cells, as carriers of octets of an N-ISDN network, are specially marked. Finally, the network adaptor also function to empty the octets from the payloads of incoming cells.
For a better understanding of the present invention, reference is made to the following description and accompanying drawings while the scope of the invention will be pointed out in the appended claims.